Bits of Security

A number associated with the amount of work (that is, the number of operations of some sort) that is required to break a cryptographic algorithm or system in some way. In this Recommendation, the security strength is specified in bits and is a specific value from the set {112, 128, 192, 256}. If the security strength associated with an algorithm or system is S bits, then it is expected that (roughly) 2S basic operations are required to break it.Source(s):NIST SP 800-90A Rev. 1 under Security Strength

A number associated with the amount of work (that is, the number of operations) that is required to break a cryptographic algorithm or system. In this policy, security strength is specified in bits and is a specific value from the set {80, 112, 128, 192, 256}.Source(s):CNSSI 4009-2015 under security strength
(CNSSI 1300)